Polyphenylene oxide processing

Polyphenylene oxide/polystyrene Processability, lower cost... 

Polyphenylene oxide and polyphenylene ether are oxides or ethers like polyoxymethylene but an aromatic unit replaces the methylene group leading to — ( — C6H4 — O—) — Polyphenylene ether has too high a glass transition temperature to be easily processed and is marketed in the form of alloys with other resins, such as ... 

In 1966, Cadotte developed a method for casting mlcroporous support film from polysulfone, polycarbonate, and polyphenylene oxide plastics ( ). Of these, polysulfone (Union Carbide Corporation, Udel P-3500) proved to have the best combination of compaction resistance and surface microporosity. Use of the mlcroporous sheet as a support for ultrathin cellulose acetate membranes produced fluxes of 10 to 15 gfd, an increase of about five-fold over that of the original mlcroporous asymmetric cellulose acetate support. Since that time, mlcroporous polysulfone has been widely adopted as the material of choice for the support film in composite membranes, while finding use itself in many ultrafiltration processes. 

Polyphenylene oxide (PPO) or Polyphenylene ether (PPE) is an amorphous polymer with a softening temperature of about 210 °C. To improve its processability it is mostly blended with PS (modified PPE, e.g. Noryl ), which is at the cost of its heat distortion temperature. The properties are excellent the applications are mainly in fine-mechanical construction, in automotive parts, in household equipment etc. 

Fortunately, the deficiencies of both the classic thermosets and general purpose thermoplastics have been overcome by the commercialization of a series of engineering plastics including polyacetals, polyamides, polycarbonate, polyphenylene oxide, polyaryl esters, polyaryl sulfones, polyphenylene sulfide, polyether ether ketones and polylmides. Many improvements in performance and processing of these new polymers may be anticipated through copolymerization, blending and the use of reinforcements. 

ORIGIN/INDUSTRY SOURCES/USES from coal tar fractionation and coal processing intermediate in manufacturing of phenolic antioxidants pharmaceuticals plastics resins disinfectants solvents insecticides fungicides rubber chemicals polyphenylene oxide dyestuffs cresylic acid constituent wetting agent additive of lubricants and gasoline... 

The Bjorklund works [169] lead us to develop a synthesis route in which the polypyrrole grows in the insulating matrix. Different solutions (PVC, polycarbonate, polyphenylene oxide,. ..) or emulsions (PTFE) of insulating polymer have been tested. In the case of PTFE-polypyrrole blend we used a classical oxidising coupling process by FeCl3 [104,127]. Comparative experiments have been performed on granular materials obtained by polypyrrole powder dispersion in an elastomer or an epoxyde resin [127]. 

Polyethers are obtained from three different classes of monomers, namely, carbonyl compounds, cyclic ethers, and phenols. They are manufactured by a variety of polymerization processes, such as polymerization (polyacetal), ring-opening polymerization (polyethylene oxide, polyprophylene oxide, and epoxy resins), oxidative coupling (Polyphenylene oxide), and polycondensation (polysulfone). 

Polyphenylene oxide (PPO) HDT, rigidity, flame retardancy Processability, impact strength... 

Modified Poiyphenyiene Ether Thermoplastic polyphenylene ether alloys with impact polystyrene. Has good impact strength, resistance to heat and fire, but poor resistance to solvents. Processed by injection and structural foam molding and extrusion. Used in auto parts, appliances, and telecommunication devices. Also called MPE, MPO, and Modified Polyphenylene Oxide. 

Electroplating chemicals n. Copper, gold, silver, chromium, and nickel are generally used as the conductive metal for plating. Acrylonitrile-butadiene-styrene resins have been most widely used for electroplated articles. Others in commercial use for the process include cellulose acetate, some grades of polypropylene, polysulfones, polycarbonate, polyphenylene oxide, nylons, and rigid PVC. 

Oxidative coupling n. A process defined as a reaction of oxygen with active hydrogen atoms from different molecules, producing water and a dimerized molecule. If the hydrogen-yielding substance has two active hydrogen atoms polymerization results. This process is used in the polymerization of phenols, particular polyphenylene oxide. 

Plastics that are readily bonded with induction methods include all grades of acrylonitrile butadiene styrene (ABS), nylon, polyester, polyethylene, polypropylene, and polystyrene, as well as those materials often considered more difficult to bond such as acetals, modified polyphenylene oxide, and polycarbonate. Reinforced thermoplastics with filler levels up to 65 pCTcent have been joined successfully. Many combinations of dissimilar materials can be bonded with induction welding processes. 

The second case we describe here is the polymerization of styrene to polystyrene in the presence of polyphenylene oxide. Poly-2,6-dimethyl-l,4-phenylene oxide (PPE) is an orange-red polymer with a glass transition temperature of 220°C and it is completely miscible with PS. Although strictly speaking the system consists of two components, the mutual complete miscibility of all components (monomer as well as both polymers) permits to treat this polymerization as a one-component reactive extrusion process. From product point of view the addition of PPE to PS results in a polymer blend with a higher glass transition temperature (6) than polystyrene. From process point of view the increased viscosity of PPO... 

The effect of moisture on the p relaxations in amorphous phenylene polymers is well documented (93-95) for many of the systems cited previously. For example, Allen and co-workers (93) determined that both the dielectric and mechanical P relaxations in polysulfone, polycarbonate, polyphenylene oxide, and polyether sulfone were dependent on the water content of the samples. In addition, the amount of water absorbed depended on the polarity of the molecule. The effect of moisture on the dielectric p process in these polymers appears to be greater than for the mechanical loss process, as illustrated in Figures 41 and 42 (93). 

Isayev A I and Subramanian P R (1991) Self-reinforced composite of thermotropic liquid crystalline polymers and process for preparing same, U.S. Patent 5,070,157, Austr Patent 645,154 (1994), Eur Patent EP 0543 953 (1997), Can Patent 2,086,931 (1993), Jap Patent 2 841 246, French Patent 0543953, Ger Patent 69125493.1, Great Brit Patent 0543953, Int Patent WO 92/03506 (1992). Isayev A I (1991) Wholly aromatic polyester fiber-reinforced polyphenylene oxide and process for preparing same, U.S. Patent 5,006,403. 

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